It depends on what they want it to do. Upgrade could've been practical, but Black's directing style would've made that prohibitively expensive.
If it's a regular Predator doing regular Predator things, mix of practical and cg are the likely options.
Man in a suit technology was used originally because it's cheap and efficient, and that has not significantly changed in 34 years for something like the Predator. If it looks like a guy in a suit, just put a guy in a suit.